#include<bits/stdc++.h>

using namespace std;
using ll = long long;
#define endl '\n'

template<typename T=int>
inline T read() {
    T x;
    cin >> x;
    return x;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    priority_queue<int, vector<int>, greater<int>> Q;//小顶堆
    //queue<int> Q;
    Q.push(3);
    Q.push(2);
    Q.push(4);
    while (Q.size()) {
        cout << Q.top() << endl;
        Q.pop();
    }


    return 0;
}
